1. Field of the Invention
The present invention generally relates to an optical disk clamper, and more particularly, to the retracting mechanism of an optical disk clamper and an optical disk drive using the same.
2. Description of the Related Art
A type of optical disk drive has an optical disk clamper held in a holding unit. When an optical disk is set in such type of optical disk drive, a turntable moves upward and the optical disk clamper fits in and is magnetically attracted by the turntable so that the optical disk is clamped on the turntable. The optical disk clamper holding unit has an opening portion through which the optical disk clamper is built in, but supports the optical disk clamper so that the optical disk clamper does not come out once built in.
FIGS. 1A–1C are schematic diagrams showing a conventional optical disk clamper holding unit 10. This optical disk clamper holding unit 10 has a surrounding unit 11, a flange unit 12, and a built-in opening unit 13. The surrounding unit 11 is shaped like a ring of which a portion is removed. The removed portion corresponds to the built-in opening unit 13. Though the built-in opening unit 13 is formed as small as possible, no devisal is employed. The flange unit 12 protrudes inwardly from the surrounding unit 11.
The optical disk clamper is shaped like a reel, and has a hub unit 21, an upper flange unit 22, and a lower flange unit 23.
The optical disk clamper 20 is built in the optical disk clamper holding unit 10 through the built-in opening unit 13 by bending the lower flange unit 23. The hub unit 21 is positioned inside of the flange unit 12 and the upper flange unit 22 is supported by the flange unit 12 in the manner that the optical disk clamper is freely movable in the optical disk clamper holding unit 10, but does not come off through the built-in opening unit 13.
Oc is the center of the optical disk clamper 20, and Oh is the center of the optical disk clamper holding unit 10.
When the turntable moves with the optical disk, the optical disk clamper 10 fits in the turn table and is magnetically attracted by the turn table, the optical disk is clamped on the turn table.
The range of clearance in which the optical disk clamper 20 is movable in the holding unit 10 will be considered as below. The optical disk clamper 20 can move in the direction of X1, X2, and Y1 until the hub unit 21 touches the flange unit 12. As showed in FIG. 1B, the optical disk clamper 20 can move the distance δX1 in the X1 direction. In the direction toward the opening unit 13, that is, the Y2 direction, however, the optical disk clamper 20 can move, as showed in FIG. 1C, until the upper flange unit 22 touches the edges 11a and 11b of the surrounding unit 11, that is, the distance δY2.
The distance δY2 is about twice the distance δY1. If the optical disk clamper 20 is moved in the holding unit 10 in the Y2 direction, there is a risk that, when the turntable moves upward with the optical disk, the optical disk clamper 10 does not fit in the turn table and the optical disk is not normally clamped.
By the way, FIG. 2 is a schematic diagram showing a conventional heat radiation mechanism of an electronic component. The heat radiation mechanism showed in FIG. 2 is employed by disk drives such as CD-R. In this heat radiation mechanism, the heat generated by a semiconductor component 220 is radiated by a bottom cover 250 that carries out the function of a heat radiation plate.
The leads 230 of the semiconductor component 220 are connected and fixed to a circuit board 210 with soldering 240. The semiconductor component 220 generates heat when it is operated.
The bottom cover 250 is attached to the disk drive so that the bottom cover 250 faces the circuit board 210. This bottom cover 250 is made of highly conductive metal plate and functions as a heat radiation plate. A heat radiation unit 260 is formed at the position opposed to the semiconductor component 220 on the bottom cover 250 so that the distance between the bottom cover 250 and the semiconductor component 220 becomes small.
Conventionally, a heat radiation sheet 270 is provided on the semiconductor component 220 to thermally connect the semiconductor component 220 and the bottom cover 250 so that this heat radiation sheet 270 touches the bottom cover 250 (heat radiation unit 260) when the bottom cover 250 is attached to the optical disk drive. The heat generated by the semiconductor component 220 is transferred to the bottom cover 250 through the heat radiation sheet 270 and radiated by the bottom cover 250.
However, in the case of the above structure wherein the heat radiation mechanism uses a portion of an apparatus (a disk drive in this case) into which the heat radiation mechanism is built as an element of the heat radiation mechanism, the performance of the heat radiation mechanism is affected by assembly error of the apparatus, manufacturing error of components, and tolerances (hereinafter, these are referred to as “assembly errors” as a whole).
That is, in the case where the assembly errors exist when the bottom cover 250 is assembled to the disk drive, and/or the case where the assembly errors exist when the circuit board 210 is assembled to the disk drive, the heat radiation sheet 270 may not touch the bottom cover 250 (heat radiation unit 260) as showed in FIG. 3. If the heat radiation sheet 270 does not touch the bottom cover 250, the heat generated by the semiconductor component 220 is not efficiently transferred to the bottom cover 250.